var t = n =0, count;
$(document).ready(function(){ 
		count=$("#banner_list a").length;
		$("#banner_list a:not(:first-child)").hide();
		$("#banner_info").html($("#banner_list a:first-child").find("img").attr('alt'));
		$("#banner_info").click(function(){
			window.open($("#banner_list a:first-child").attr('href'), "_blank")
		});
		$("#banner li").click(function() {
				var i = $(this).text() -1;//获取Li元素内的值，即1，2，3，4
				n = i;
			if (i >= count) return;
			$("#banner_info").html($("#banner_list a").eq(i).find("img").attr('alt'));
			$("#banner_info").unbind().click(function(){
				window.open($("#banner_list a").eq(i).attr('href'), "_blank")
			})
			$("#banner_list a").filter(":visible").fadeOut(500).parent().children().eq(i).fadeIn(1000);
				document.getElementById("banner").style.background="";
			$(this).toggleClass("on");
			$(this).siblings().removeAttr("class");
		});
		t = setInterval("showAuto()", 3000);
		$("#banner").hover(function(){
			clearInterval(t)
			},function(){
				t = setInterval("showAuto()", 3000);
			});
});
	
	function showAuto(){
	    n = n >=(count -1) ?0 : ++n;
	    $("#banner li").eq(n).trigger('click');
	}